Recently, a method for estimating three-dimensional acoustic impedance profiles in cultured cells and human dermal organs was proposed by interpreting the reflected ultrasonic signal based on a 1-D transmission line model for acoustic impedance microscopy (AIM). However, AIM has a disadvantage that reflected signals from cells overlap with that from a reference substrate. Additionally, the amplitudes of the reflected signals from the specimens are significantly weaker than that from the substrate. In this paper, we proposed a new method for separation of those signals based on a concept of clutter filter, which had been developed for a color Doppler method in medical ultrasonic imaging. The proposed filter using singular value decomposition (SVD) could separate original signals into desired signals such as those from the substrate and cells. Additionally, an effect from a tilt of the substrate was investigated in this study. Separability of the proposed filter was evaluated by two investigations. First one was to evaluate the separability by estimating a correlation coefficient between the filtered signal and signal reflected from a position only with the substrate. Second one was to compare a slope of the substrate estimated from the original signal with that estimated from the filtered signals from the substrate. The experimental results showed that the proposed filter could separate signals from the substrate, and the compensation of the tilt of the substrate could improve the performance of the proposed filter.

最近，通过解释基于声阻抗显微镜 (AIM) 的一维传输线模型的反射超声信号，提出了一种估计培养细胞和人体皮肤器官中三维声阻抗分布的方法。然而，AIM 有一个缺点，即来自细胞的反射信号与来自参考基板的信号重叠。此外，来自样品的反射信号的幅度明显弱于来自基板的信号。在本文中，我们基于杂波滤波器的概念提出了一种分离这些信号的新方法，该方法是为医学超声成像中的彩色多普勒方法开发的。所提出的使用奇异值分解 (SVD) 的滤波器可以将原始信号分离为所需信号，例如来自基板和细胞的信号。此外，本研究还研究了基板倾斜的影响。所提出的过滤器的可分离性通过两项研究进行评估。第一个是通过估计滤波信号和仅从基底位置反射的信号之间的相关系数来评估可分离性。第二个是将根据原始信号估计的底物斜率与根据来自底物的过滤信号估计的斜率进行比较。实验结果表明，所提出的滤波器可以将信号与基板分离，基板倾斜的补偿可以提高所提出的滤波器的性能。第一个是通过估计滤波信号和仅从基底位置反射的信号之间的相关系数来评估可分离性。第二个是将根据原始信号估计的底物斜率与根据来自底物的过滤信号估计的斜率进行比较。实验结果表明，所提出的滤波器可以将信号与基板分离，基板倾斜的补偿可以提高所提出的滤波器的性能。第一个是通过估计滤波信号和仅从基底位置反射的信号之间的相关系数来评估可分离性。第二个是将根据原始信号估计的底物斜率与根据来自底物的过滤信号估计的斜率进行比较。实验结果表明，所提出的滤波器可以将信号与基板分离，基板倾斜的补偿可以提高所提出的滤波器的性能。